We have shown that immunologic monitoring during the first thirty days post-transplant has no significant predictive value for clinical success or failure with rejection episodes as an endpoint. Since most rejection episodes occur in the 5th and 6th weeks we will now concentrate on the period of 30-90 days post-transplant. In addition we will begin to establish the parameters necessary to determine whether renal allograft recipients acquire specific modulation of their ability to mediate cell mediated cytotoxicity directed toward donor antigens. In addition, we will pursue development of techniques to detect recipient specific anti donor lymphocyte dependent antibody (LDA).